body {
    font-family: Arial, sans-serif;
    line-height: 1.8;
    margin: 20px;
    background-color: #f8f9fa;
    color: #212529;
}
.container {
    background-color: #ffffff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    /* Removed width, margin:auto, overflow from ch5 original to match ch1 style */
}
h1, h2, h3 {
    color: #007bff;
}
h1 { /* Main page/chapter title */
    text-align: center;
    border-bottom: 2px solid #007bff;
    padding-bottom: 15px;
    margin-bottom: 30px;
}
h2 { /* Section titles */
    margin-top: 40px;
    border-bottom: 1px solid #dee2e6;
    padding-bottom: 10px;
    /* color: #333; from ch5 was different, using ch1's color via h1,h2,h3 rule */
}
/* h3 styling is covered by the h1,h2,h3 rule from ch1, 
   ch5 original .content-section h3 { color: #555; } is not needed 
   as .content-section is being removed/restructured. */
p, li {
    margin-bottom: 15px;
}
ul {
    padding-left: 20px;
}
pre {
    background-color: #2d2d2d; /* Dark grey background from ch1 */
    color: #f8f8f2;           /* Light grey/white text from ch1 */
    padding: 1em;             /* Padding from ch1 */
    border-radius: 6px;       /* Border-radius from ch1 */
    overflow-x: auto;
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace; /* Font from ch1 */
    font-size: 0.9em;         /* Font-size from ch1 */
    border: 1px solid #444;   /* Border from ch1 */
}
/* Code style from ch1 for pre > code */
pre > code {
    background-color: transparent;
    color: inherit;
    padding: 0;
    font-size: inherit;
}
/* Inline code style from ch1 */
code {
    background-color: #f0f0f0;
    color: #333333;
    padding: 0.2em 0.4em;
    border-radius: 3px;
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;
    font-size: 0.9em;
}

/* Specific code highlighting styles from ch5 (to be added to ch1's base pre/code) */
.code-comment {
    color: #7f9f7f; /* Green for comments */
}
.code-keyword {
    color: #cc7832; /* Orange for keywords */
}
.code-string {
    color: #a5c261; /* Light green for strings */
}
.code-function {
    color: #ffc66d; /* Yellow for functions */
}
.code-class {
    color: #da4939; /* Red for classes */
}

.navigation { /* Style from ch1 */
    margin-top: 30px;
    text-align: center;
}
.navigation a {
    text-decoration: none;
    background-color: #007bff;
    color: white;
    padding: 10px 20px;
    border-radius: 5px;
    margin: 0 10px;
    transition: background-color 0.3s ease;
}
.navigation a:hover {
    background-color: #0056b3;
}

/* .note style from chapter2_models.html, for consistency */
.note {
    background-color: #e7f3fe;
    border-left: 6px solid #2196F3;
    padding: 15px;
    margin: 20px 0;
}

/* Removed styles specific to ch5's old structure like header, nav, footer, .back-link, .content-section */
